The three keepers - The priests who stood at the door to receive the offerings of the people, see 2 Kings 20:9, and 2 Kings 23:4.
Matthew Henry
Concise Bible Commentary
The leaders of the Jews caused them to err; but now they are, in particular, made monuments of Divine justice. Here is an account of two earlier captivities. This people often were wonders both of judgment and mercy.
SDA Bible Commentary (limited)
Volume 1-7
24. The chief priest. Not only the political leaders, but the religious heads of the nation as well, were destroyed. Only a short time prior to this, Zephaniah, the second priest, had heard Jeremiah predict the death of Jerusalem’s leaders (ch.21:1, 7).